Nutritional Science Midterm 1 Study Guide Nutrition the process of obtaining and the assimilation of food necessary for the health maintenance growth and reproduction of the organism o Functions of nutrients Forming structures Providing Energy o 3 functional categories of nutrients Those that provide energy kcal Those important for growth and development Those that keep bodily functions running smooth o Absorptive processes of nutrient absorption FAPE Facilitated diffusion Active absorption Passive diffusion Endocytosis Composition of the human body o 62 water o 16 fat o 16 protein o 6 minerals carbs etc Carbohydrates the body s main source of energy and should be the major part of total daily intake macronutrient Contain carbon hydrogen and oxygen o Types of carbohydrates Simple Monosaccharides glucose fructose galactose Disaccharides sucrose lactose maltose Complex Oligosaccharides 3 10 monosaccharides Polysaccharides starch fiber glycogen Better blood glucose control More nutritious with fewer calories Ex grains beans peas potatoes o Functions of carbohydrates Provide energy Spare protein Provide sweetness Provide fiber Enhances function of some proteins Break down fat to carbon dioxide and water Can be converted to fatty acids if excess calories are consumed Fiber the material that gives plants texture and support Primarily made up of carbohydrates but not usually broken down by the body for energy o Types of fiber Soluble Lowers blood glucose levels Lowers cholesterol Dissolves in water Can be found in a variety of fruits and vegetables apples oatmeal rye dried beans Insoluble Doesn t dissolve in water because it contains a high amount of Can be found in the bran of grains pulp of fruit and skin of cellulose vegetables Speeds up digestion Promotes weight loss Lowers risk of colon cancer Fat supplies energy and transports nutrients o Two families of essential fatty acids Omega 3 Omega 6 Canola oil flaxseed oil cold water fish or fish oil Primrose or black current seed oil o Essential fatty acids are required for the body to function normally o Increased consumption of essential fatty acids lowers the risk of cardiovascular diseases and cancer and alleviates symptoms of arthritis PMS dermatitis and inflammatory bowel syndrome Protein supplies amino acids to build and maintain healthy body tissue Necessary for all aspects of metabolism and growth o Amino Acids 20 building blocks of proteins The body must have them in the right amounts to function properly Foods from animals milk and eggs usually contain the essential but a 12 are manufactured in the body 8 essential are provided by the diet variety of plant products can also provide them protein complementation Amino acid pool an accumulation of amino acids in the liver and blood that adjusts to meet the body s need for protein and amino acids Limiting amino acid because our bodies ned amino acids to be in specific ratios to each other the amino acid that is too low to match with the rest is the limiting amino acid Structure Each amino acid contains a central carbon bound to a hydrogen atom an amino group an acid group and a side chain Peptide bonds link amino acids together and are formed between the acid group of one amino acid and nitrogen group of the next Dipeptide bonds are formed between two amino acids Polypeptide bonds are formed between many amino acids o A protein is made up of one or more polypeptide chains folded into a three dimensional shape Protein shape determines function Types Essential must be supplied by diet Nonessential can be made by the organism o Transamination the body s creation of a nonessential amino acid when it is not available from the diet Ketogenic produces ketone bodies following chemical alteration Glucogenic can be converted to glucose if necessary The deamination of an amino acid produces ammonia NH3 and a keto acid o Protein Functions Enzymes speed up metabolic reactions Transport proteins move substances in and out of cells Antibodies help the immune system fight off foreign bodies Contractile proteins help the muscles to move Hormones are chemical messengers insulin and glucagon Proteins help regulate fluid and acid base balance o Central Dogma Information in an organism is encoded in the DNA DNA is then copied into RNA From the information in the RNA you can then make the protein o Proteins in the diet Adult RDA 0 8 g kg 1kg 2 2lbs Infant RDA 1 5 g kg Elderly RDA 1 0 g kg 40 80 g day normal protein need range o Protein Nitrogen balance Increased protein positive nitrogen balance pregnant women Healthy nitrogen equilibrium Deathly ill negative nitrogen balance Nitrogen balance B Nitrogen intake I urinary fecal skin o Estimating protein quality Apparent digestibility Neaten Nfecal Neaten x 100 o Factors that affect protein quality Digestibility Amino acid content Toxins Trypsin inhibitor Form of amino acids PER live weight gain crude protein intake o Protein Efficiency Ratio o Phenylketonuria individuals with this Aspartame contains phenylalanine o Protein deficiency PKU inherited disease due to a defective gene Proteins harm Protein energy malnutrition PEM refers to the many conditions like Kwashiorkor protein deficiency and Marasmus total energy deficiency o Too much protein o Protein excess causes heart disease obesity cancer and osteoporosis Hydration and kidney function increases water loss Kidney stones Heart disease and cancer due to increased fat and decreased fiber Food protein allergies o Food proteins allergens cause an immune response allergic reaction o 8 foods account for 90 of all food allergies peanuts tree nuts milk eggs fish shellfish soy and wheat o Celiac disease wheat gluten intolerance Vegetarian diets o Types vegan lacto ovo vegetarian lacto vegetarian semi vegetarian o Nutrient concerns o Low in fat and cholesterol B12 calcium iron zinc vitamin D riboflavin protein quality Vitamins organic substances present in food and required by the body in small amounts for the regulation of metabolism and maintenance of normal growth and functioning o Water soluble o Fat soluble vitamins B C vitamins A D E K Minerals important component of muscles tissues and bones and important component of many life supporting systems like hormones oxygen transport and enzyme systems Minerals the body needs in large quantities Ex calcium phosphorous magnesium sodium potassium sulfur and o Major minerals chloride o Trace minerals Only needed in small amounts and participates in most